Information is displayed on large areas in the known manner by normal projection with an overhead projector. Because of the necessary magnification involved, the intensity of the direct illumination must be very high. This results in problems with respect to long-term stability and service life.
State of the art developments in liquid crystal display technology also facilitate the provision of large-area display panels, whereby small liquid crystal displays are arranged in matrix form. In this case, the gap size between the small displays determines the resolution of the overall display. The size of the optically not usable areas is determined by the width of the hermetic frame of the individual elements and the width of the electric contacting.
In De 30 40 551 A1, which describes a different display species, it is suggested that these areas can be partially reduced by implementing auxiliary assembly means. Hereby, the supporting plates of the individual liquid crystal display units are joined only on those sides where there are no adjacent display units, for which purpose a resin seal is used. The display electrodes of adjacent display units can be moved closely together.
In yet another different species, DE-40 04 739 A1 describes an optical system for stereoscopically presenting information, with an optical element having a lens function, a light source and an at least partially transparent flat-shaped information carrier, in which two light sources are arranged on that side of the optical element opposing the observer, and where the information carrier is located in the area of the aperture diaphragm of the optical element. In this system, the image is created in the eye of the beholder, so that no projection surface is required. The avoidance of optically not usable zones is not being strived for.